A pipe string may be placed in a borehole during drilling, completion and/or servicing operations involving the borehole. One or more components may be connected together to form a pipe string. These components may include drill pipe, drill collars, drilling motors, drill bits, stabilizers, telemetry tools, steering tools, logging tools, completion tools, servicing tools, casing, tubing, coiled tubing, and/or other equipment.
During such drilling, completion and/or servicing operations, the pipe string or components of the pipe string may become stuck in the borehole. The risk of sticking is increased in “extended reach” boreholes, which may include lengthy non-vertical or horizontal sections.
Sticking of a pipe string may sometimes be prevented, and freeing of a stuck pipe string may sometimes be accomplished by vibrating the pipe string axially, torsionally and/or laterally.
Vibrating a pipe string may involve operating one or more vibration tools which may be incorporated into the pipe string. Examples of vibration tools in the prior art include UK Patent Application No. 2 261 238 A (Reiley), Russian Patent Publication No. RU2139403 C1 (Panfilov), Soviet Union Patent Publication No. SU 1633087 A1 (Lyakh et al), U.S. Pat. No. 4,384,625 (Roper et al), U.S. Pat. No. 4,667,742 (Bodine), U.S. Pat. No. 4,830,122 (Walter), U.S. Pat. No. 7,191,852 (Clayton), U.S. Pat. No. 7,708,088 (Allahar et al), U.S. Patent Application Publication No. US 2002/0157871 A1 (Tulloch), U.S. Patent Application Publication No. US 2009/0173542 A1 (Ibrahim et al), U.S. Patent Application Publication No. US 2010/0212965 A1 (Hall et al), U.S. Patent Application Publication No. US 2010/0212966 A1 (Hall et al), and U.S. Patent Application Publication No. US 2010/0224412 A1 (Allahar).
There remains a need for a relatively simple and robust vibration tool which may be connected with a pipe string in order to vibrate the pipe string.